Vacuum lightning-arrester.



P. S. CHAPMAN & J. T. GREENE.

VACUUM LIGHTNING ARRESTER.

APPLIOATIOK FILED NOV. 20, 1909.

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FRANK SPENCER CHAPMAN AND JOHN TYLER GREENE, OF TOLEDO, OHIO, TO THE NATIONAL ELECTRIC SPECIALTY COMPANY, OF TOLEDO, OHIO, A CORPORA- 'noN or OHIO.

vacuum LIGHTNING-ARBESTER.

Application filed November 20, 1909. Serial No. 529,137.

.To all whom it may concern:

Be it known that we, FRANK S. CHAPMAN and JOHN T. GREENE, citizens of the United States, and residents of Toledo, in the county of Lucas and State of Oh10,. have invented certain new and useful Improvements in Vacuum Lightning-Arresters, of which the following is a specification.

Our invention relates to vacuum lightning arresters and it consists in the combinations, constructions and arrangements of parts herein described and claimed.

An object of our invention 1s to provide a protector against lightning to be used primarily with electric light and power wires which will furnish a good path for a static discharge, but at the same time will diminish the liability of the destruction of the arrester from the heat caused by the formation of the are by the service current.

A further object of our invention is to provide a vacuum lightning arrester having great efiiciency and yet consisting of comparatively few. parts and therefore of economical construction.

A further .object of our invention is to provide a lightning arrester in which the static discharge is compelled to take a roundabout or crooked path and to be split up into a number of parts, thereby diminishing the heating effect and prolonging the life of the device.

Further objects and advantages will appear in the following specification and the novel features of the device will be particularly pointed out in the appended claims.

Our invention is illustrated in the accompanying drawings forming a part of this specification in which similar reference characters indicate like parts in the several views, and in which:

Figure 1 is a central section through the device; Fig. 2 is a perspective View showing the relation of the terminals and the barrier plate; Fig. 3 is a side view of the barrier plate, and Fig. 4 is a detail section I tending projection 2, to which we secure the electrodes 3 and 4. The relative sizes of these electrodes is shown in Fig. 2. The electrode '3 is preferably provided with a non-conducting plate 3 of mica or other suitable insulating material having perforations 3 through which the conical-shaped projections 3 extend, as clearly shown in Fig. 4. The electrode 4 has a similar plate 4 provided with perforations 4 through which the projections 4 extend. Interposed between the plates 3 and 4 is a nonco-nducting barrier 5 which is of preferably greater extent than the plates or electrodes both as to length and breadth as clearly shown in Fig. 2. This barrier is by preference perforated at 5 and these perforations are disposed so that they lie midway between the vertical and horizontal rows of projections on the plates 3 and 4 the position of the latter projections being indicated at 3 in Fig. 3. From this figure it Specification of Letters Patent. Patented Feb. 20,1912.

will be seen that each projection is equallyv distant from any one of four perforations. The barrier in the form of device shown D is mounted upon the inwardly project-ing portion 2 of the wall of the chamber 1. Mounted on the exterior walls of the chamber 1 are the contacts 6 and 7 which are connected by means of the conductors 6 and 7 to the plates 4 and 3, respectively. These conductors 6 and 7 are arranged to be held by means of the spring contacts 8 and 9 as shown in Fig. 1. The vacuum arrester thus made may be inserted between a pair of stationary spring clips such as that shown at 8 and 9 of Fig. 1, and is ready for immediate use. A high static discharge finds a ready means of escape from the pointed projections 4 and 3 but since there are four equally available paths through the perforations of the barrier, the discharge will ordinarily take place in more than one path. Moreover, this path is a crookedand elongated way and therefore the tendency of the service current to form a permanent arc is reduced to a minimum. In addition to the discharge passing through the perforations of the barrier, part of it may pass around the edges of the barrier.

We claim:

1. A vacuum lightning arrester, comprising a chamber, a central perforated insulating barrier located in said chamber, and a pair of conducting plates having inwardly lation with said projeetions,,said electrodes exte mately equi-distant from a plum 1.0-

g perforate 2. In a ing rojections, and a non-conducting barrier etween-theelectrodes, said barrier having-perforations which are in staggered relation with said projections and so placed that the projections are severallv approxility of perf plate.

forations. r 3, A lightning arrester, comprising, in combination, a pair of electrodes provided with projections on adjacent faces, and between said electrodes anon-conductingba'rrier formed with openlngs 1n staggered 'reprojections directed toward said lightning arrester electrodes hav discharge between the e a barrier of non-conducting material with a plurality of openings out of line .with said stantially. equidistant from the same, res. spectivel 5. A l combinationga vacuum chamber, a pair of electrodes therein formed with projections,

=nonconducting coverings o'n the-adjacent face of said electrodes having openings through which said projections extend, and

'a .barrier'of non-conducting material between said electrodes.

"j 6. A: lightning arrester comprising in combination ah evacuated glass vessel, a pair of carbon plates within-"the vessel at opposite sides thereof cons tituting negative and positive electrodes, and a non-conducting barrier arranged between the plates to provide an opening or openings for the lectrodes.

FRANK SPENCER CHAPMAN.

JOHN TYLER GREENE.

Witnessesq LOUIS L. D. CHAPMAN, EDWARD M. N EUHAUSEL.

points of discharge andsub i g'li'tning arrester comprising in 

